Abrading apparatus



Feb. 15, 1944. A w. KEEPER ABRADING APPARATUS 3 Sheets-Sheet 1 Filed Sept. 5, 1941 Feb. 15, 1944. w. L. KEEFER ABRADING APPARATUS Filed Sept. 5, 1941 3 Sheets-Sheet 2 mzz r 2.1?efer M Feb. 15, 1944. w. KEEFER ABRADING APPARATUS Filed Sept. 5. 1941 5 Sheets-Sheet 3 wfl mipea zflonadamim Patented Feb. 15, 1944 ABRADING APPARATUS Walter L. Keefer, Hagerstowm Mi, assignor to Pangborn Corporation, Hagerstown, Md., a corporation of Maryland Application September 5, 1941, Seria1 No. 409,719

Claims.

is discharged onto the inner ends of the blades at a predetermined point or zone, the abrasive subsequently being discharged from the ends of the blades in a predetermined zone.

In providing an improved centrifugal wheel for throwing abrasive, it is a major object of this invention to provide a novel transfer mechanism which is inherently capable of being designed to discharge abrasive onto the inner ends of the" rotor throwing blades at a predetermined point or zone without the use of a circumferentially extending slotted cage. Y

A further object of this invention is the provision of a novel transfer mechanism having abrasive distributing vanes adapted to collect the abrasive delivered thereto in a series of individual charges and deliver said charges of abrasive at a predetermined point or zone, the latter being predetermined by a selective shaping Of the abra sive contacting surfaces of the vanes.

Still a further object of this invention is the provision of a novel transfer mechanism and feed means therefor, the two combinin to deliver abrasive onto the inner ends of the main throwing blades of the rotor of a centrifugal wheel at a predetermined point or zone without thenecessity for any circumferentially extending control means. i

A further object of this invention is to provide a novel transfer mechanism having abrasive distributing vanes, the shapes of which maybe designed to deliver abrasive onto the inner ends of the main throwing blades of a rotor at any predetermined point or zone relative to the point of feed to the transfer means.

Still a further object of this invention is the provision of a novel transfer mechanism wherein the abrasive isretained therein for a minimum of time, thus saving the mechanism from 'undue wear and reducing the power required to operate the mechanism.

A further object of this invention is the provision of a novel centrifugal wheel whereirithe parts are of relatively simple construction, of long life, and easily accessible for replacement and repair.

Further objects and advantages of their-wention will appear from the following description and claims taken in connection with the appended drawings, wherein:

Figure 1 is a front elevation of a preferred embodiment of the present invention illustrating the method of installation thereof in a housing.

Fig. 2 is a section taken on the line 2-2 of Fig. 1.

Fig. 3 is a section taken on the line 33 of Fig. 2.

Fig. 4 is a front elevation of the spout extension and guard a normally assembled onthe housingwall.

Fig. 5 is a View similar to Fig. 4 with the guard and spout extension disassembled.

Fig. 6 is an elevation of a portion of the front of the housing with the feed spout omitted.

" Fig, 7 is an exploded view of the several parts of the wheel of Fig. 2 illustrating their method of assembly.

Fig. 8 is a section taken on the line Fig. 1.

Fig. 9 is a section taken on the line 99 of Fi 1. V

Fig. 10 is a side elevation of the guard.

Fig. 11 is a diagrammatic illustration of amodification of the transfer mechanism of Fig. 3.-

' Referring to Figures L2, and 3, the present invention is illustrated therein as embodied in-a centrifugal wheel of the downb'last type. The wheel is preferably mounted in a housing H having side walls ii and i2, front and rear walls l3 and I4, and a top I5 which is hinged at It and provided with fastening means at l'l to permit of access to the wheel. Suitable wear plates 13 are provided inside the housing to protect the interior surfaces of the side walls from the flying abrasive. The housing H may be supported on asuitable base by angieirons IS, the bottom of the housing being open to permit a portion of the wheel to project therethrough and discharge abrasive downwardly onto the workpiece.

While the illustrated embodiment is 'of the downblast type, it is to be understood that the invention herein described is universal in application in that it can be embodied in wheels arranged to discharge upwardly or to either 'side.

The wheel proper is mounted ona' shaft 20,

extending through an opening 2| in thes'housing by suitable driving means, such as an electric motor (not shown). A flange 22 is secured to the end of the shaft 20, a second flange 23 of larger diameter being secured to the flange 22 to support a rotor assembly R. The rotor assembly R includes a disc 25, a series of sector plates 26 secured to the face of the disc, one or more abrasive propelling blades 21, and a circumferential ring 28 for securing the outer ends of the blades. To facilitate assembly, a third centering flange 23' is provided on the face of the flange 23.

The sector plates 26 (Fig. 3) are secured to the disc 25 by screws 29, the adjacent edges of the plates being spaced apart and beveled to form grooves to receive beveled flanges 3| on the abrasive propelling blades 21, as shown in Fig. 9. In securing the blades in the grooves, the ring 28 is slid toward the shaft side of the wheel to open the outer ends of the grooves between the sector "plates '26. The blades 2'! are inserted in the grooves, the ring 28 is then returned to its original position, and the blades moved radially outwardly until a projecting portion 32 on each blade locks in a groove 33 formed on the inside of the 'ring'28. i

The abrasive feed means includes a feed spout "'34, the upper endof which is formed with a-flange "35 'havin'gholes therein to receive bolts 3E5, which engage corresponding holes in an angle bracket 31, "secured as by bolts 38 to the wall l3 of the hous- As shown in Figs. 2 and 7, the feed-spout i l is of a shape to permit a free, unobstructed flow of abrasive, "the latter being fed into the opentop of the spout bygravity'from'asuitable elevated hopper (not shown). The wall l3 of thehousing H "and the wear plate 18 secured thereto are formed with an opening 39 substantially coaxial with the opening 2| to receive a holder' l'l' having a cylindrical section l2 fitting within the'openin'gtl' and a flange 'positioned'to engage a recess Minthe wall l3 adjacent the opening 39. The holder M is preferably secured in position by" clamps45 (Figs. 1, 6, and8) engaging the'fla'rigeWi-l and securedto the wall l3 of the housing by bolts E6.

The holder 41 is formed with an open'ingll to receive aflange 4B on the end of a feedspout extension #9, the'la'tter having an opening 50 therein to receive a shoulderbl on the lower end of the feed spout 34. A flange'E2 is provided on .the lower end of the "feed spout "3 3 to be engaged by a clamp 53 (Fig. 1 secured to the holderdlby a bolt 54. To prevent leakage around the connectionrbetween the lower end of the 'feed spout 34 and the endof the spout extension' t a gasket .55 is preferablyprovided in the position shown in Fig. 2. V

The spout extension 49 is provided with a flange .56 extending from a central boss 51 for about -270 as shown in Figs. 4 and 5, the flange being secured to the holder 41 as by bolts 58. V The boss 51 is formed with a passage 59 therein arranged to substantially match with the discharge end of the feed spout 3d and direct the abrasive therefrom into the interior of the transfer means. It will be noted that the passage 59 is substantially straight and unobstructed, thus providing a relatively smooth and unobstructed path for the flow of abrasiveinto the transfer mechanism.

The boss 51 is preferably formed with a hollow section 60 immediately above the passage 59 to reduce weight and economize on material. It will also be notedthat the exterior of the boss 51 immediately counterclockwise of passage 59 (Fig. 3)

abrasive and consequently greater-efficiency of the wheel.

It has also been found desirable to remove a portion of the right wall of the discharge end of the passage 59, as viewed in Fig. 3 at 62, this con struction permitting a greater unobstructed flow of abrasive in a path slightly inclined in the direction of rotation of the wheel.

arranged to abut against the outer end of the flange 23' of the rotor, and held in engagement therewith to rotate with the rotor by .a bolt 56 (Fig. 2) or similar fastening means passin through a hole in an interior boss 61. The-impeller or vaned member 64 is formed with a cylindrical portion '68 terminating adjacent the inner edges of the blades 21, and a second spaced hollow and generally frustum-shape'd section "59 spaced therefrom and connected thereto by a series of impeller vanes ll. The inner surface of the section 59 is preferably-curved at 12to aid in the guiding of the abrasive onto the innerends of the vanes H. A projecting flange T3 is provided about the section 69 to cooperate with a rib 14 formed on the interior of aguard 'liof arcuate shape (Figs. 2 and?) The section-69 is also provided with a radial flange 16 arranged to likewise cooperate with the rib l4 of the guard 15 and guard 15.

The guard i5 is formed as an arcuate shield (Fig. 3) .about a portion of the periphery-of the impeller 84, and is, provided withan-arcuate flange 19 (Figs. 4 and 5), which is shaped to flt within theopen section of the flange 56 of the spout extension 49, as shown -in-Fig. 4, the two elements is unassembled relation being shown in Fig.5.

The guard is'secured to the holder 41 byany suitable fastening means, such asscrews 81.

The impeller vanes H are 3 circumferentially spaced from one another as shown in Fig. .3, .their forward surfaces comprisinga-substantially radial face 82 anda forwardly inclined surface-.83. In the embodiment illustrated wherein the-abrasive is fed downwardly from the passage '59 onto the inner ends of the vanes, the abrasive-is collected in individual charges by faces 82 0f .the vanes, and subsequently discharged along :SllT- -faces.83 by centrifugalforce. It has'been found that-by varying the inclination and-curvature of the surfaces 83 which contact the abrasive, that the rate of flow of the abrasive there'over .can be accelerated or retarded as desired. In the instant case, the inclination and cunvatureissuch as to retard the discharge of the abrasive .until the vanes ll reach approximatelythe :12 oclock position at the left end of guard-l5. as viewedrin Fig. 3. At this selected point, the abrasive is discharged onto theinner ends-ofthe blades 21, the

discharge therefrom beginning atapproximately further around the periphery of the wheel,

and being ina downward direction.

The guard 15 functions to collect the stray particles of abrasive which are discharged fromthe vanes II at Other than the desired point of discharge and return themto the mainstream of abrasive. e r i The serrations 63 function as deflectors for the abrasive particles contacting the outside of the spout extension 49 immediately counterclockwise of the point of feed and return the particlesback into the path of the vanes I l 1 i In operation, abrasiveis fed through the feed spout 34 and the passage 59 of the spout exten sion 49 in a substantially continuous stream onto the inner ends of the vanes H of the impeller 64. By reason of its connection to .the rotor R, the impeller (it and the vanes 1| rotate at thesame speed'as the rotor, which is usually about 2200 R. P. M. By reason of their movement, the faces 82 of the vanes H divide and collectthe abrasive stream into a series of individual charges which move outwardly on the forwardly curved surfaces 83 until discharged from the ends of the vanes at approximately the 12 oclock position (Fig. 3). Any stray particles that are discharged prematurely are collected by guard 15 and returned to the path of the main flow of abrasive.

As the number of vanes 1| preferably corre sponds to the number of'blades 21 and the former are preferably positioned with their discharge ends immediately forward of the inner ends of the blades 27, the individual charges of abrasive from the several vanes H are discharged at the proper time and in a direction corresponding to the direction of movement of the blades 21, so that the abrasive encounters the inner ends of the blades with a minimum impact. This positioning of the impeller vanes II with reference to the blades 21 is insured by any suitable key and slot arrangement, as by the provision of a screw 9| in the flange 23' which engages a slot 92 in the face 65 of the impeller 64.

In addition, the abrasive charges have a considerable speed by reason of their being thrown from the vanes I I by centrifugal force which speed increases the efiiciency of the wheel both as to abrading characteristics and directional control.

If it is desired to change the direction of discharge of the wheel, either the curvatur of the vanes H can be altered to discharge the abrasive charges at different points, or within a limited range, the position of the guard 15 can be changed. For instance, referring to Fig. 3, if it is desired to feed the abrasive onto the rotor blades at about the 10 oclock position, vanes H of the type shown can be used, and the guard rotated counterclockwise so that its left end terminates adjacent the desired point of discharge. Under these conditions, the abrasive charges will still be discharged from the vanes 1| at about the 12 oclock position. However, the abrasive will be thrown against the inner surface of the guard in a direction nearly tangential to that surface, and will continue along the inner surface of the uard until discharged from the end thereof.

To discharge in a sidewise direction, as to the right, as viewed in Fig. 3, the guard 15 may be positioned as shown in Fig. 11, the passage 59 being adjusted clockwise a short distance to discharge abrasive at a point slightly forward of the position shown in Fig. 3. The impeller is provided with vanes 1 I which are formed with rearwardly curved surfaces 82' terminating in substantially radial faces 93. With this arrangement, the individual charges of abrasive pass rapidly along surfaces 82' to the surfaces 83' from which they are discharged onto the inner ends of the blades 21 in the direction indicated by the arrows; In this modification, the guard 15 functions to return stray particles of abrasive to the main stream. 7

It will be noted that the vaned impeller 64 of the present invention functions not only as an impeller, in imparting speed to the abrasive, but also to insure its discharge at a predetermined point or zone onto the inner ends of the rotor blades. Thus it performs a dual function. Moreover, by reason of the ability to change the curvature and shape of the impeller vanes, the direction of discharge :onto the inner ends of the rotor blades can be varied so as to adjust the point or zone of discharge from the periphery of the wheel.

By reason of the fact that no circumferentially extending cage or the like is required in which the abrasive particles may be swirled around a number of times before being discharged, there is considerably less wear on the parts of the trans fer mechanism contacting the abrasive, and less power is required for its operation.

It is to be understood that the invention may be embodied in specific forms other than that illustrated without departing from the principal or essential characteristics thereof. The embodiments shown are therefore to be considered as illustrative and not restrictive, the scope of the invention being definedby the appended claims rather than the foregoing description and drawings. All modifications and changes which come within the meaning and range of equivalency of the claims are therefore intendedto be included therein.

I claim:

1. Apparatus for centrifugally propelling abrasive in a down blast direction without the use of a control cage comprising, a rotor, a plurality of radially arranged propeller blades carried by the rotor extending inwardlyshort of the axis of said rotor to define a central space, a feed spout forguiding abrasive into said central space, a feed! spout extension mounted in said central space including a cylindrical boss having a passage there-- in in opening communication with said feed spout. discharging the abrasive at the periphery of the boss in a downward direction radially towards the path described by the inner ends of said propeller blades, an impeller mounted in said central space rotating with the rotor, a plurality of circumferentially spaced radially inclined vanes carried by the impeller arranged around said boss, said vanes equalling the number of propeller blades and extending from points adjacent the periphery of said boss to points adjacent the inner ends of said propeller blades, an arcuate abrasive contacting surface on each vane curved forwardly with respect to the direction of rotation and with all axial dimensions thereon parallel with the axis of the impeller whereby the abrasive is picked up by said vanes and retarded by the arcuate surfaces thereon and thrown therefrom into the path of movement of the inner ends of the propeller blades at an uppermost point in the rotation thereof, and an arcuate shaped guard member extending over a fraction of the periphery of the impeller terminating adjacent said uppermost point.

2. In abrading apparatus, a rotor, a plurality of circumferentially spaced abrasive propelling blades carried by said rotor terminating to define a central opening between the inner ends thereof, a feed spout, a feed spout extension including a cylindrical boss arranged in said central opening and having a passage therein communicating with said vfeed spout and discharging abrasive at the periphery of said boss, an impeller within said central opening and secured to said rotor, 'cir cumferentially spaced vanes carried by said impeller and arranged around said boss to pickup the abrasive issuing from said passage, an annular radial flange carried by .the impeller at each end of said vanes, another, annular flange projecting axially. from one of said radialflanges,

an arcuate shaped stationary guard member embracing a portion .of the impeller, and inwardly projecting arcuate ribs carried by the guard member cooperating with said annular flanges to prevent the escape of abrasiveaxially of the impeller.

3. A mechanism for transferring abrasive particles from a feed spout to the blades of centrifugal abrading apparatus comprising, a feed spout-extension including a cylindrical boss having a passage therein communicating with the feed spout and discharging abrasive at the periphery of said boss, a rotatable impeller including circumferen- 4. In abradingvapparatus, a 11313013184 plurality of "circumferentially spaced abrasive propelling bladescarried by said rotor terminating to define a central opening between the inner endsthereof, a feed spout, a feed spout, extension including 'a cylindrical boss arranged in said central opening-andhaving a passage therein communiscating with-said 'feed spout and discharging abra-- sive at the periphery of said boss, anjmpeller within said central opening and secured to said rotor,circumferentially spaced vanes carried by said impeller and arranged aroundsaid boss to pick up the abrasive issuing from said .passagepa flange carried by said boss havingva peripheral opening therein, an arcuate shaped guard mema ber extending around a portion of said impeller, and an arcuate flange carried by said guardmember fitting within the opening in said-flange.

5. In abrading apparatus, a feed spout, a feed spout extension including a cylindrical boss having a passage therein communicating withsaid feed spout for discharging abrasive at the periphery of said boss, a rotatable impeller including a plurality of vanes arranged to revolve around said boss and pick up the abrasive issuing from said passage, a radial flange carried by said-boss adjacent-one end of the impeller vanes, saidfiange having a sector-shaped opening therein, an arcuate shaped guard member extending circumferentially around a portion of the impeller, and a sector-shaped flange on the guard member fitting the sector-shaped opening in said radial flange.

WALTER L. KEEFER. 

